Chong-Suh Lee, Jin-Sung Park, Yunjin Nam, Youn-Taek Choi, and Se-Jun Park
It has been well documented that optimal sagittal alignment is highly correlated with good clinical outcomes in adult spinal deformity (ASD) surgery. However, it remains to be determined whether the clinical benefit of appropriately corrected sagittal alignment can be maintained in the long term. Therefore, the aim of this study was to investigate whether appropriately corrected sagittal alignment continues to offer benefits over time with regard to clinical outcomes and mechanical failure.
Patients older than 50 years who underwent ≥ 4-level fusion for ASD and were followed up for ≥ 5 years were included in this study. Appropriateness of sagittal alignment correction was defined as pelvic incidence minus lumbar lordosis ≤ 10°, pelvic tilt ≤ 25°, and sagittal vertical axis ≤ 50 mm. Two groups were created based on this appropriateness: group A (appropriate) and group IA (inappropriate). Clinical outcomes were evaluated using the visual analog scale (VAS), Oswestry Disability Index (ODI), and Scoliosis Research Society Outcomes Questionnaire–22 (SRS-22). The development of mechanical failures, such as rod fracture and proximal junctional kyphosis (PJK), was compared between the two groups.
The study included 90 patients with a follow-up duration of 90.3 months. There were 30 patients in group A and 60 patients in group IA. The clinical outcomes at 2 years were significantly better in group A than in group IA in terms of the VAS scores, ODI scores, and all domains of SRS-22. At the final follow-up visit, back VAS and ODI scores were still lower in group A than they were in group IA, but the VAS score for leg pain did not differ between the groups. The SRS-22 score at the final follow-up showed that only the pain and self-image/appearance domains and the total sum were significantly higher in group A than in group IA. The incidence of rod fracture and PJK did not differ between the two groups. The rate of revision surgery for rod fracture or PJK was also similar between the two groups.
The clinical benefits from appropriate correction of sagittal alignment continued for a mean of 90.3 months. However, the intergroup difference in clinical outcomes between groups A and IA decreased over time. The development of rod fracture or PJK was not affected by the appropriateness of sagittal alignment.
Chong-Suh Lee, Kyung-Chung Kang, Sung-Soo Chung, Ki-Tack Kim, and Seong-Kee Shin
The aim of this study was to examine the results of microbiological cultures from local bone autografts used in posterior lumbar interbody fusion (PLIF) and to identify their association with postoperative spinal infection.
The authors retrospectively evaluated cases involving 328 patients who had no previous spinal surgeries and underwent PLIF for degenerative diseases with a minimum 1-year follow-up. Local bone was obtained during laminectomy, and microbiological culture was performed immediately prior to bone grafting. The associations between culture results from local bone autografts and postoperative spinal infections were evaluated.
The contamination rate of local bone was 4.3% (14 of 328 cases). Coagulase-negative Staphylococcus (29%) was the most common contaminant isolated, followed by Streptococcus species and methicillin-sensitive Staphylococcus aureus. Of 14 patients with positive culture results, 5 (35.7%) had postoperative spinal infections and were treated with intravenous antibiotics for a minimum of 4 weeks. One of these 5 patients also underwent reoperation for debridement during this 4-week period. Regardless of the microbiological culture results, the infection rate after PLIF with local bone autograft was 2.4% (8 of 328 cases), with 5 (62.5%) of 8 patients showing positive results on autograft culture.
The incidence of contamination of local bone autograft during PLIF was considerable, and positive culture results were significantly associated with postoperative spinal infection. Special attention focused on the preparation of local bone for autograft and its microbiological culture will be helpful for the control of postoperative spinal infection.
Jin-Sung Park, Se-Jun Park, Chong-Suh Lee, Tae-hoon Yum, and Bo-Taek Kim
Several radiological parameters related to the aging spine have been reported as progression factors of early degenerative lumbar scoliosis (DLS). However, it has not been determined which factors are the most important. In this study the authors aimed to determine the risk factors associated with curve progression in early DLS.
Fifty-one patients with early DLS and Cobb angles of 5°–15° were investigated. In total, 7 men and 44 women (mean age 61.6 years) were observed for a mean period of 13.7 years. The subjects were divided into two groups according to Cobb angle progression (≥ 15° or < 15°) at the final follow-up, and radiological parameters were compared. The direction of scoliosis, apical vertebral level and rotational grade, lateral subluxation, disc space difference, osteophyte difference, upper and lower disc wedging angles, and relationship between the intercrest line and L5 vertebra were evaluated.
During the follow-up period, the mean curve progression increased from 8.8° ± 3.2° to 19.4° ± 8.9°. The Cobb angle had progressed by ≥ 15° in 17 patients (33.3%) at the final follow-up. In these patients the mean Cobb angle increased from 9.4° ± 3.4° to 28.8° ± 7.5°, and in the 34 remaining patients it increased from 8.5° ± 3.1° to 14.7° ± 4.8°. The baseline lateral subluxation, disc space difference, and upper and lower disc wedging angles significantly differed between the groups. In multivariate logistic regression analysis, only the upper and lower disc wedging angles were significantly correlated with curve progression (OR 1.55, p = 0.035, and OR 1.89, p = 0.004, respectively).
Asymmetrical degenerative change in the lower apical vertebral disc, which leads to upper and lower disc wedging angles, is the most substantial factor in predicting early DLS progression.
Se-Jun Park, Keun-Ho Lee, Chong-Suh Lee, Joon Young Jung, Jin Ho Park, Gab-Lae Kim, and Ki-Tack Kim
The goal of this study was to evaluate the radiographic and clinical results of instrumentation surgery without fusion for metastases to the spine.
Between 2010 and 2017, patients with spinal tumors who underwent instrumentation without fusion surgery were consecutively evaluated. Preoperative and postoperative clinical data were evaluated. Data were inclusive for last follow-up and just prior to death if the patient died. Instrumentation-related complications included screw migration, screw or rod breakage, cage migration, and screw loosening.
Excluding patients who died within 6 months, a total of 136 patients (140 operations) were recruited. The average follow-up duration was 16.5 months (median 12.4 months). The pain visual analog scale score decreased from 6.4 to 2.5 (p < 0.001) and the Eastern Cooperative Oncology Group scale score improved (p < 0.001). There were only 3 cases (2.1%) of symptomatic instrumentation-related complications that resulted in revisions. There were 6 cases of nonsymptomatic complications. The most common complication was screw migration or pull-out (5 cases). There were 3 cases of screw or rod breakage and 1 case of cage migration. Two-thirds of the cases of instrumentation-related complications occurred after 6 months, with a mean postoperative period of 1 year.
The current study reported successful outcomes with very low complication rates after nonfusion surgery for patients with spinal metastases, even among those who survived for more than 6 months. More than half of the instrumentation-related complications were asymptomatic and did not require revision. The results suggest that nonfusion surgery might be sufficient for a majority of patients with spinal metastases.
Kyung-Chung Kang, Chong-Suh Lee, Seung-Kee Shin, Se-Jun Park, Chul-Hee Chung, and Sung-Soo Chung
Thoracic ossification of the ligamentum flavum (OLF), a main cause of thoracic myelopathy, is an uncommon disease entity. It is seen mostly in East Asia, although the majority of reports have issued from Japan. In the present study, the clinical features and prognostic factors of thoracic OLF were examined in a large number of Korean patients.
Data from 51 consecutive patients who underwent decompressive laminectomy with or without fusion for thoracic OLF between 1998 and 2008 were retrospectively analyzed. Patients were evaluated pre- and postoperatively using the modified Japanese Orthopedic Association (JOA) scale (maximum total score of 11). Patient age, sex, preoperative symptoms, duration of initial symptoms, number of involved segments, duration of follow-up, presence of dural adhesion (dural tearing), intramedullary high signal intensity, morphological classification of OLF (axial or sagittal), coexisting disease, and fusion or no fusion were also evaluated. Surgical outcomes were assessed using JOA recovery rate/outcome scores, and patient satisfaction grades and prognostic factors were analyzed.
There were 18 men and 33 women with a mean age of 60.9 years (range 38–80 years). A mean preoperative JOA score of 5.5 improved to a mean score of 7.4 at the last follow-up (mean 52 months after surgery). The mean duration of the initial symptoms was 34.5 months (range 0.1–240 months) prior to surgery. The most common symptoms were motor dysfunction (80%); sensory deficit (67%); and pain, numbness, and claudication (59%) in the lower extremities. Knee hyperreflexia appeared in 69% of the patients. There were a total of 130 ossified segments, and the mean number of segments per patient was 2.6. Ninety-two (71%) of 130 segments were located below T-8. Recovery outcomes were good (18 patients), fair (16 patients), unchanged (11 patients), or worse (6 patients). Thirty-one patients (61%) were satisfied with their operations. Patients with a beak type of OLF on sagittal MR images experienced a higher recovery rate and a better satisfaction grade than did those with a round OLF. The patients with higher preoperative JOA scores demonstrated significantly higher JOA scores postoperatively (p < 0.001), and the preoperative JOA score had a significant correlation with the recovery rate in patients exhibiting mainly motor dysfunction (p = 0.040, r = 0.330).
Of the thoracic OLF studies published to date, the present analysis involves the largest Korean population. The most common symptoms of thoracic OLF were motor dysfunction and sensory deficit in the lower extremities, although pain, numbness, and claudication were observed in some patients and were notably accompanied by knee hyperreflexia. At a minimum of 2 years after surgery for thoracic OLF, operative outcomes were generally good, and the prognostic factors affecting good surgical outcomes included a beak type of OLF and a preoperative JOA score > 6.
Chong-Suh Lee, Kyung-Chung Kang, Sung-Soo Chung, Won-Hah Park, Won-Ju Shin, and Yong-Gon Seo
There is a lack of evidence of how back muscle strength changes after lumbar fusion surgery and how exercise influences these changes. The aim of this study was to evaluate changes in back muscle strength after posterior lumbar interbody fusion (PLIF) and to measure the effects of a postoperative exercise program on muscle strength and physical and mental health outcomes.
This prospective study enrolled 59 women (mean age 58 years) who underwent PLIF at 1 or 2 spinal levels. To assess the effects of a supervised lumbar stabilization exercise (LSE), the authors allocated the patients to an LSE (n = 26) or a control (n = 33) group. The patients in the LSE group performed the LSEs between 3 and 6 months postoperatively. Back extensor strength, visual analog scale (VAS) scores in back pain, and physical component summary (PCS) and mental component summary (MCS) scores on the 36-Item Short Form Health Survey were determined for the both groups.
Mean strength of the back muscles tended to slightly decrease by 7.5% from preoperatively to 3 months after PLIF (p = 0.145), but it significantly increased thereafter and was sustained until the last follow-up (38.1%, p < 0.001). The mean back muscle strength was similar in the LSE and control groups preoperatively, but it increased significantly more in the LSE group (64.2%) than in the control group (21.7%) at the last follow-up 12 months after PLIF (p = 0.012). At the last follow-up, decreases in back pain VAS scores were more significant among LSE group patients, who had a pain reduction on average of 58.2%, than among control group patients (reduction of 26.1%) (p = 0.013). The patients in the LSE group also had greater improvement in both PCS (39.9% improvement) and MCS (20.7% improvement) scores than the patients in the control group (improvement of 18.0% and 1.1%, p = 0.042 and p = 0.035, respectively).
After PLIF, strength in back muscles decreased until 3 months postoperatively but significantly increased after that period. The patients who regularly underwent postoperative LSE had significantly improved back strength, less pain, and less functional disability at 12 months postoperatively.